1. Field of the Invention
The present invention relates to a transmission. More particularly, the present invention relates to an automatic friction wheel transmission.
2. Description of the Prior Art
Numerous innovations for transmissions have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
FOR EXAMPLE, U.S. Patent No. 3,581,853 to Hoff teaches a two-speed chain transmission for minibikes, as original equipment or as a conversion kit. High- and low-speed sprockets on a jackshaft are chain driven at different speeds by high and low drive sprockets carried by a centrifugal clutch on the engine shaft. The jackshaft is chain connected to the rear wheel of the bike. The low speed driven sprocket is mounted on the jackshaft by an overrunning clutch which permits the jackshaft to overrun the low drive when it is driven by the high drive. The high-speed sprocket is mounted on the jackshaft by a clutch which is disengageable to let the low-speed drive takeover. A brake acts on the jackshaft on the driven side of the clutches.
ANOTHER EXAMPLE, U.S. Pat. No. 3,604,279 to Davis teaches an engine output shaft that drives the input member of a clutch having a plurality of friction members normally confined around a hub by a garter spring. The clutch has two output drums, each having a sprocket thereon coupled by a chain to a sprocket on a jackshaft which is, in turn coupled through sprockets and a chain to a vehicle drive wheel. The drums have internal surfaces engageable by the friction members due to centrifugal force as the engine speed increases. The drums are of different internal diameter for sequential engagement, and the jackshaft sprockets associated therewith are also of different diameters for a low-speed drive first, and then a high-speed drive.
STILL ANOTHER EXAMPLE, U.S. Pat. No. 4,328,877 to Ballard teaches an automatic two-speed drive system for a vehicle having two drive wheels. A first drive wheel is connected to the drive source through a low-speed hub which is disengaged when the wheel reaches a pre-determined rotational speed. The second drive wheel is connectable to the drive source through a high-speed hub which becomes engaged when the drive source reaches a predetermined rotational speed.
YET ANOTHER EXAMPLE, U.S. Pat. No. 4,972,736 to Koshimo teaches a stepless speed-change transmission for a vehicle having an acceleration clutch, comprising a fluid coupling, a forward/backward change-over mechanism coupled to a rear stage of the acceleration clutch, and a stepless speed changer coupled to a rear stage of the forward/backward change-over mechanism; a centrifugal lock-up clutch for the stepless speed-change power transmission for vehicle characterized by that an approximately disc-like output hub is connected to a turbine wheel of a fluid coupling fixed to an output shaft of said acceleration clutch, two side plates are so provided as to sandwich both side faces of the output hub, a damper mechanism is interposed between the side plate and the output hub, and a clutch shoe is provided at an outer peripheral portion of the side plate, which is movable in a radial direction of the side plate by means of a centrifugal force and can be freely engaged with or disengaged from an input member inputting a power from an engine.
STILL YET ANOTHER EXAMPLE, U.S. Pat. No. 3,328,419 to Motl et al. teaches a two-speed transmission for driving an alternator or other engine accessory includes an enclosed gear case. An output shaft passes through both ends of the rear case. Bearings supported on the gear case support the ends of the output shaft. A tubular input shaft surrounds the output shaft and is journaled on the output shaft between the two output shaft support bearings. A planet gear carrier is rotatively journaled on the output shaft inside the gear case. Compound planet gears are rotatively supported by the planet gear carrier with one planet of each compound planet gear in mesh with a sun gear on the tubular input shaft and with a planet of each compound planet gear in mesh with a sun gear on the output shaft. A brake assembly is either applied to lock the planet gear carrier to the gear case or is released to let the planet carrier rotate in the gear case. When the tubular input shaft is driven and the brake assembly holds the planet carrier, torque is transmitted from the input shaft to the input sun gear to the first planet gear to the second planet gear to the output sun gear and to the output shaft. When the brake assembly is released, torque passes from the tubular input shaft directly to the output shaft through a one-way clutch and the input and output shafts run at the same speed. A lubrication system lubricates critical bearings in the transmission.
FINALLY, YET STILL ANOTHER EXAMPLE, U.S. Pat. No. 5,445,567 to Chattin teaches a derailer for derailing a drive chain from one sprocket to an adjacent sprocket of a multi-stage sprocket assembly wherein operation of the derailer thereof is automatically controlled by centrifugal force so that the driving chain is automatically shifted to higher gears as the speed of the bicycle increases.
It is apparent that numerous innovations for transmissions have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.